Nuclear import of metallothionein requires its mRNA to be associated with the perinuclear cytoskeleton.
J Biol Chem
; 274(49): 34961-6, 1999 Dec 03.
Article
em En
| MEDLINE
| ID: mdl-10574972
ABSTRACT
The influence of mRNA localization on metallothionein-1 protein distribution was studied by immunocytochemistry. We used Chinese hamster ovary cells that had been transfected with either a native metallothionein-1 gene construct or metallothionein-1 5'-untranslated region and coding sequences linked to the 3'-untranslated region from glutathione peroxidase. The change in the 3'-untranslated region caused the delocalization of the mRNA with a loss of the perinuclear localization and association with the cytoskeleton. Clones were selected which expressed similar levels of metallothionein-1 protein, as assessed by radioimmunoassay. The results showed that loss of metallothionein-1 mRNA localization was associated with a loss of metallothionein-1 protein localization, most notably with a lack of metallothionein-1 protein in the nucleus of synchronized cells which were beginning to synthesize DNA. This indicates that the association of metallothionein-1 mRNA with the cytoskeleton around the nucleus is essential for efficient shuttling of the protein into the nucleus during the G(1) to S phase transition. This is the first demonstration of a physiological role for perinuclear mRNA localization and we propose that such localization may be important for a wide range of nuclear proteins, including those that shuttle between nucleus and cytoplasm in a cell cycle dependent manner.
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Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto
/
RNA Mensageiro
/
Núcleo Celular
/
Metalotioneína
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article